It’s probably too late for Mayor Bob Walkup and the Tucson City Council to turn the renovation of downtown over to private investors.

Too bad. But after being stonewalled for years, Old Tucson founder Bob Shelton and developers Humberto Lopez and Allan Norville may not want the job now.

Shelton proposed building Colonial Tucson, a tourist attraction west of the Santa Cruz River, to show visitors and residents how Tucson looked in the 19th century and before.

Lopez begged the city for a decade or more to let him expand his Hotel Arizona into a first-class convention hotel. The hotel previously sported the brands of Braniff, Marriott and Holiday Inn.

And Norville spent years seeking city approval to build a permanent exhibition hall for his gem and mineral dealers with his own money on his own land near the Tucson Convention Center. (I did some consulting for him in his early efforts).

Various city officials said no to all three plans, insisting their own downtown plan would succeed if they designed, supervised and built it.

First came the aquarium, then the rainbow bridge, then a new bus depot.

Those projects apparently are dead now.

The city lobbied legislators for a law to fund downtown renewal by diverting incremental sales taxes to fund their Rio Nuevo project. The money would come from retail sales, not only downtown but extending east along Broadway all the way to Park Place. The bill passed in 1999, the same year Walkup became mayor.

Shelton’s Colonial Tucson project and a Wild West Museum suggested by retired advertising executive Earl Wettstein won’t be built.

Because there’s no exhibition building, Norville still erects Tucson’s largest tent each year to house gem and mineral dealers from every continent except Antarctica.

And Lopez is still waiting to see the first shovel of dirt turned for the convention hotel.

Last April, the mayor and council beamed as they accepted applause and high fives for approving a $130 million arena, $64 million to renovate the existing convention center and $250 million for the convention hotel project.

They also agreed to buy the Hotel Arizona from Lopez for $28 million and Norville’s seven acres near the old El Paso train station for $17 million.

Arena Digest’s website noted the decision came less than a week after the council had received a consultant’s feasibility study for the arena. The fact that Norville had submitted his own plan to develop the hotel and convention center area probably sped the city’s pace.

Now we’ve learned that last year’s cost estimates were far too low. The arena will cost $166 million, plus $30 million or more for furnishings.

The new hotel and the convention center renovation will cost at least $270 million.

And the city still hasn’t bought the old hotel from Lopez or Norville’s land. The council’s lofty promises last year have raised the market value for those properties.

One council member suggested asking the private sector to build the arena, but no one has stepped forward.

Businesses can only donate so much to government. Dunn-Edwards Paints and Tofel Construction answered a city appeal to repaint the A on Sentinel Peak red, white and blue for free after St. Patrick’s Day fans had painted it green.

But why would any firm volunteer to solve the mess downtown unless the city turns over most of its Rio Nuevo money and stays out of it otherwise?

Ever the optimist, Walkup told KVOI radio talkshow host John C. Scott he’s not concerned about the higher costs for downtown.

He should be. He also should call a special council meeting for staff, stakeholders and citizens to discuss how to move ahead.

Instead, Walkup compared the situation to telling your architect about all the features you want in your new custom home and then cutting back a little when the cost is more than you can afford.

Scott, many of his listeners and I will have to take the mayor’s word for that.

Our non-custom homes didn’t take nine years to build.

Contact Steve Emerine or e-mail comments for publication to editor@azbiz.com. Emerine, a Tucson resident since 1960, has run Steve Emerine Strategic Public Relations since 1994. He is a former local newspaper reporter, editor and columnist and served as Pima County Assessor from 1973 to 1980. He is a regular Monday guest on the John C. Scott radio talk show, which airs from 6 a.m. to 7 a.m. and from 11 a.m. to noon weekdays on The Voice KVOI 690-AM. This column appears weekly in Inside Tucson Business.